Question: Before the previous stop there were 98 people riding on a train. 18 people ended up getting off at the stop. How many people are riding the train now?
Solution: The number riding the train now is the difference between the number who were riding and the number who got off at the previous stop. The difference is $98 - 18$ people on the train. $98 - 18 = 80$ people are on the train.